No abstract

A simple relation between the bulk modulus, plasmon energy, electronic polarisability are given for ternary chalcopyrite semiconductors. Bulk modulus has been evaluated from plasmon energy by proposing a linear relation between them. From bulk modulus electronic polarisability has been evaluated. The estimated values are in good agreement with the experimental values and earlier researchers.

No abstract

No abstract

The effect of shock on 3C and 6H phases of silicon carbide was investigated within our earlier developed scaled binding energy based Debye–Gru¨neisen model. Required input parameters for the equation of state (EOS) model were obtained from density functional theory calculations using PBE-GGA functional as well as a nonlocal exchange-correlation functional B3LYP. In our earlier calculations using PBE-GGA functional, we predicted the phase transition from 3C to B1 phase at about 68 GPa, which deviated significantly from the experimental value of about 100 GPa. An empirical energy correction was applied in that case to obtain the experimental transition pressure. However, in the present work, we observed that if hybrid B3LYP functional is employed to calculate EOS parameters, shock induced phase transitions from 3C to B1 and 6H to B1 phases occur at about 102 GPa and 105 GPa, respectively, in close agreement with experiments without invoking any empirical correction. We obtained good agreement of our predictions with experimental shock data using a simple model of metastability and the hybrid B3LYP functional, which accounts for exchange-correlation effects better than the PBE-GGA functional in the case of SiC.